Variable speed unit



June 13, 1944. A. RAFTER I I VARIABLE SPEED UNIT Filed April 14, 1942 2 sheetsi-sneet 1 A ORN EY June 13, 1944. A I A F E 2,351,148

VARIABLE SPEED UNIT Filed April 14, 1942 2 Sheets-Sheet 2 INVENTOw BY I ATTORNEY Patented June 13, 1944 VARIABLE SPEED UNIT Albert Rafter, Glen Ridge, N. J., assignor to Rafter Machine Company, Belleville, N. J., a partnership of New Jersey Application April 14, 1942, Serial No. 438,961 3 Claims." (o1. 74-23mm This invention relates to variable speed units, and more particularly to the provision of a simple structure for automatically adjusting elements of such units.

Variable speed units of the type herein considered embody a plurality of expansible pulleys, or movablesheaves, having bevelled faces engaging tapered belts. The variations in speed are attained b adjusting the effective diameters of the pulleys engaging the belts by expanding or contracting the pulleys by; moving the sheaves of the pulleys laterally.

Heretofore, various devices have been employed for laterally moving the sheaves of the pulleys. However, such adjusting devices have been complicated in that they embodied the use of springs, levers, etc., which increased materially the cost of the structure.

It is, therefore, an object of this invention to provide in a variable speed unit a simple arrangement by means of which the parts of the unit can be automatically adjusted without the use of springs, and associated levers.

A further object of the invention is the provision of a variable speed unit in which the driven shaft is in alinement with the driving shaft which enables a compact structure adapted for use in many situations requiring variable speed drives.

A further object is the provision of a variable speed unit including a plurality of expansible pulleys with elements capable of being quickly and automatically adjusted to obtain various pitch diameters of the pulleys and corresponding varying speeds.

These and other advantageous objects, which will later appear, are accomplished by the simple and practical construction and arrangement of parts hereinafter described and exhibited in the accompanying drawings, forming part hereof, and in which:

Fig. 1 is an elevational view, partly in section, of a variable speed unit embodying the invention, and

Fig. 2 is an end view of the unit, taken partly in section, on line 2-2 of Fig. 1.

Referring to the drawings, the variable speed unit is shown to comprise a casing I, havin a wall 2 thereof provided with a bearing 3, through which passes a driving shaft 4, connected to a motor or the like (not shown). Fixed to shaft 4 by means of pin 5 is a collar 6 integral with a sheave I having a bevelled face 8 which cooperates with the bevelled face 9 of a sheave ID to act upon a tapered belt I l. The sheave II] has its hub |2 keyed at l3 to shaft 4 so that the sheave II) can be moved laterally towards and away from sheave I.

Passing through bearings l4 and [5 in the walls 2 and Hi of the casing is a shaft Keyed to shaft IT at I8 is a central sheave l9 having opposite bevelled faces 20 and 2|. Loosely and r0- tatably mounted on shaft I1 is a sheave 22 having a bevelled face 23 cooperating with bevelled face 20 to act onbelt Loosely and rotatably mounted on shaft I! on the opposite side of sheave I9 is a sheave 24 having a bevelled face 25 cooperating with bevelled face 2| t0-act on a tapered belt 25. Passing through sheave I9 is a bolt 21 to which is secured sheaves 22 and 24, so that the two sheaves can be moved laterally together in the same direction. Integral with sheave 24 is a collar 28 having a peripheral groove 29 in which is positioned. a fork 30 integral with a hub 3| which threadedly engages a shaft 32 passing through wall I6 and an extension of bearing l5, and having attached thereto a hand wheel 33 by means of a pin 34. The hub 35 for the hand wheel abuts the bearing l5, and together with nut 36 prevents longitudinal movement of shaft 32.

Passing through a bearing 31 in wall IB is a driven shaft 38 to which is secured by means of pin 39 the hub 40 of a sheave 4| having a bevelled face 42, engaging the belt 26.

The shaft 38 has a reduced portion 43 loosely positioned in a recess in the end of shaft 4. The hub of sheave 4| has an extension 44 to which is keyed at 41 a sheave 45 having a bevelled face 46 engaging belt 26 to enable the sheave 45 to be moved laterally towards or away from sheave 4|. The sheave 45 has a hub 48 which is rotatably mounted on hub l2 by means of ball bearings 49.

In operation, to vary the speed, the hand wheel 33 is rotated to move the sheaves 22 and 24 laterally. For example, if the sheaves are moved to the left, the effective diameter of the pulley formed by faces 20 and 23 will be decreased and the effective diameter of the pulley formed. by faces 2| and 25 will be increased, causing a tightening or pull on belt 26 and a loosening of belt II. The pull on belt 26 urges sheave 45 to the left thus decreasing the diameter of the pulley formed by faces 42 and 46. At the same time faces 8 and 9 will be moved towards each other thus increasing the diameter of the pulley formed thereby. By such an adjustment, the speed of the driven shaft is increased. Similarly, by operating the hand wheel to move sheaves 22 and sheave, a sheave keyed to the other fixed sheave for lateral movement thereon relative thereto, hubs on said keyed sheaves disposed toward each other in overlapping spaced relation, and bearing means interposed between said overlapping portions to cooperate in the relativ rotation thereof.

. 2...ln .a variable speed .unit,.a casing a driving shaft and a driven shaftrotatably'supported in said casing in alignment with each other, a

isheave fixed to said driving shaft and a sheave "fixed to said driven shaft, a sheave keyed to one of sheaves could be employed to get anyidesired.

ratio and any desired speed or torque on the driven shaft.

The foregoing disclosure is 'td be regarde'dcasl descriptive and illustrative only, and not as restrictive 0r limitative of theiinventiompftwhich obviously, many embodiments may be constructed, including many modifications, without degparting zfrom the.- spirit :-.and--.,=scope: of-the invention herein set forth and'denoted in the iappen'dzeclaclaims.

Having thus :described -my invention, what I --c1aim:as1new' and desire tosecure by Letters'Pat- -=-ent-;.:is 1

.;1. In ia variablespeed-unit, acasing, adri-Ving shaft :and a driven .:shaft rrotatably supported in said casing in alignment with --each sother, .a :sheave fixed to said drivingzshaft :and a Tsheave ifixedztolsaid:idrivenvshaft,':a.:sheave-keyedrto one of gsaid z'sha'fts :for -:rotation: therewith and for lateral movement thereon -.r.elativ.e to the :fixed ao'fmaid-shafts for rotation therewith and for lateral .movement thereon relative to the fixed :.'sheave,-',a-sheaveikeyed to the other fixed sheave -'lfor latera1;movement thereon relative thereto, hubs'on'said keyed sheaves disposed toward each other in overlapping relation, and means inter- ,Dosedbetween said overlapping portions to cooperatein the relative rotation thereof.

E3..zInca"variablesspeedc-unit,eascasing;a :driving shaft andz-aadriven gshaft rotatabiyisupportediin :said :casirrg tin alignment with :each iother, a sheave fixed to said driving shaft .andraisheave fixed ftO'iSfiid-"dliVGIl?$h&ft,i'a;YSheaYe rkeyedito 'one .:of:said shafts-for rotationirtherewith"and fortlatzeral I movement 'TthBIBOIl t're'lative 3130 '.the fixed --sheave,:az-sheavmkeyedito therotherfixed :sheave :for lateral 'movement ith'ereon relative rthereto, 'fhubs onrsai-di keyed sheaveszand overlapping-por- 1 tions :on .i'said ihu'b :for cooperative .iengagement in the relative rotation of saiii hu'bs. 1 

